Commit 705b52fe authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: cbc - Convert from skcipher to lskcipher 



Replace the existing skcipher CBC template with an lskcipher version.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 32a8dc4a

crypto/cbc.c

+61 −102
Original line number Diff line number Diff line
@@ -5,8 +5,6 @@ 
 * Copyright (c) 2006-2016 Herbert Xu <herbert@gondor.apana.org.au>

 */



#include <crypto/algapi.h>

#include <crypto/internal/cipher.h>

#include <crypto/internal/skcipher.h>

#include <linux/err.h>

#include <linux/init.h>
@@ -14,99 +12,71 @@ 
#include <linux/log2.h>

#include <linux/module.h>



static int crypto_cbc_encrypt_segment(struct skcipher_walk *walk,

				      struct crypto_skcipher *skcipher)

static int crypto_cbc_encrypt_segment(struct crypto_lskcipher *tfm,

				      const u8 *src, u8 *dst, unsigned nbytes,

				      u8 *iv)

{

	unsigned int bsize = crypto_skcipher_blocksize(skcipher);

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	struct crypto_cipher *cipher;

	struct crypto_tfm *tfm;

	u8 *iv = walk->iv;



	cipher = skcipher_cipher_simple(skcipher);

	tfm = crypto_cipher_tfm(cipher);

	fn = crypto_cipher_alg(cipher)->cia_encrypt;

	unsigned int bsize = crypto_lskcipher_blocksize(tfm);



	do {

	for (; nbytes >= bsize; src += bsize, dst += bsize, nbytes -= bsize) {

		crypto_xor(iv, src, bsize);

		fn(tfm, dst, iv);

		crypto_lskcipher_encrypt(tfm, iv, dst, bsize, NULL);

		memcpy(iv, dst, bsize);



		src += bsize;

		dst += bsize;

	} while ((nbytes -= bsize) >= bsize);

	}



	return nbytes;

}



static int crypto_cbc_encrypt_inplace(struct skcipher_walk *walk,

				      struct crypto_skcipher *skcipher)

static int crypto_cbc_encrypt_inplace(struct crypto_lskcipher *tfm,

				      u8 *src, unsigned nbytes, u8 *oiv)

{

	unsigned int bsize = crypto_skcipher_blocksize(skcipher);

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	struct crypto_cipher *cipher;

	struct crypto_tfm *tfm;

	u8 *iv = walk->iv;



	cipher = skcipher_cipher_simple(skcipher);

	tfm = crypto_cipher_tfm(cipher);

	fn = crypto_cipher_alg(cipher)->cia_encrypt;

	unsigned int bsize = crypto_lskcipher_blocksize(tfm);

	u8 *iv = oiv;



	if (nbytes < bsize)

		goto out;



	do {

		crypto_xor(src, iv, bsize);

		fn(tfm, src, src);

		crypto_lskcipher_encrypt(tfm, src, src, bsize, NULL);

		iv = src;



		src += bsize;

	} while ((nbytes -= bsize) >= bsize);



	memcpy(walk->iv, iv, bsize);

	memcpy(oiv, iv, bsize);



out:

	return nbytes;

}



static int crypto_cbc_encrypt(struct skcipher_request *req)

static int crypto_cbc_encrypt(struct crypto_lskcipher *tfm, const u8 *src,

			      u8 *dst, unsigned len, u8 *iv, bool final)

{

	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);

	struct skcipher_walk walk;

	int err;



	err = skcipher_walk_virt(&walk, req, false);

	struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);

	struct crypto_lskcipher *cipher = *ctx;

	int rem;



	while (walk.nbytes) {

		if (walk.src.virt.addr == walk.dst.virt.addr)

			err = crypto_cbc_encrypt_inplace(&walk, skcipher);

	if (src == dst)

		rem = crypto_cbc_encrypt_inplace(cipher, dst, len, iv);

	else

			err = crypto_cbc_encrypt_segment(&walk, skcipher);

		err = skcipher_walk_done(&walk, err);

	}

		rem = crypto_cbc_encrypt_segment(cipher, src, dst, len, iv);



	return err;

	return rem && final ? -EINVAL : rem;

}



static int crypto_cbc_decrypt_segment(struct skcipher_walk *walk,

				      struct crypto_skcipher *skcipher)

static int crypto_cbc_decrypt_segment(struct crypto_lskcipher *tfm,

				      const u8 *src, u8 *dst, unsigned nbytes,

				      u8 *oiv)

{

	unsigned int bsize = crypto_skcipher_blocksize(skcipher);

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	struct crypto_cipher *cipher;

	struct crypto_tfm *tfm;

	u8 *iv = walk->iv;



	cipher = skcipher_cipher_simple(skcipher);

	tfm = crypto_cipher_tfm(cipher);

	fn = crypto_cipher_alg(cipher)->cia_decrypt;

	unsigned int bsize = crypto_lskcipher_blocksize(tfm);

	const u8 *iv = oiv;



	if (nbytes < bsize)

		goto out;



	do {

		fn(tfm, dst, src);

		crypto_lskcipher_decrypt(tfm, src, dst, bsize, NULL);

		crypto_xor(dst, iv, bsize);

		iv = src;
@@ -114,83 +84,72 @@ static int crypto_cbc_decrypt_segment(struct skcipher_walk *walk, 
		dst += bsize;

	} while ((nbytes -= bsize) >= bsize);



	memcpy(walk->iv, iv, bsize);

	memcpy(oiv, iv, bsize);



out:

	return nbytes;

}



static int crypto_cbc_decrypt_inplace(struct skcipher_walk *walk,

				      struct crypto_skcipher *skcipher)

static int crypto_cbc_decrypt_inplace(struct crypto_lskcipher *tfm,

				      u8 *src, unsigned nbytes, u8 *iv)

{

	unsigned int bsize = crypto_skcipher_blocksize(skcipher);

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *);

	unsigned int nbytes = walk->nbytes;

	u8 *src = walk->src.virt.addr;

	unsigned int bsize = crypto_lskcipher_blocksize(tfm);

	u8 last_iv[MAX_CIPHER_BLOCKSIZE];

	struct crypto_cipher *cipher;

	struct crypto_tfm *tfm;



	cipher = skcipher_cipher_simple(skcipher);

	tfm = crypto_cipher_tfm(cipher);

	fn = crypto_cipher_alg(cipher)->cia_decrypt;

	if (nbytes < bsize)

		goto out;



	/* Start of the last block. */

	src += nbytes - (nbytes & (bsize - 1)) - bsize;

	memcpy(last_iv, src, bsize);



	for (;;) {

		fn(tfm, src, src);

		crypto_lskcipher_decrypt(tfm, src, src, bsize, NULL);

		if ((nbytes -= bsize) < bsize)

			break;

		crypto_xor(src, src - bsize, bsize);

		src -= bsize;

	}



	crypto_xor(src, walk->iv, bsize);

	memcpy(walk->iv, last_iv, bsize);

	crypto_xor(src, iv, bsize);

	memcpy(iv, last_iv, bsize);



out:

	return nbytes;

}



static int crypto_cbc_decrypt(struct skcipher_request *req)

static int crypto_cbc_decrypt(struct crypto_lskcipher *tfm, const u8 *src,

			      u8 *dst, unsigned len, u8 *iv, bool final)

{

	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);

	struct skcipher_walk walk;

	int err;

	struct crypto_lskcipher **ctx = crypto_lskcipher_ctx(tfm);

	struct crypto_lskcipher *cipher = *ctx;

	int rem;



	err = skcipher_walk_virt(&walk, req, false);



	while (walk.nbytes) {

		if (walk.src.virt.addr == walk.dst.virt.addr)

			err = crypto_cbc_decrypt_inplace(&walk, skcipher);

	if (src == dst)

		rem = crypto_cbc_decrypt_inplace(cipher, dst, len, iv);

	else

			err = crypto_cbc_decrypt_segment(&walk, skcipher);

		err = skcipher_walk_done(&walk, err);

	}

		rem = crypto_cbc_decrypt_segment(cipher, src, dst, len, iv);



	return err;

	return rem && final ? -EINVAL : rem;

}



static int crypto_cbc_create(struct crypto_template *tmpl, struct rtattr **tb)

{

	struct skcipher_instance *inst;

	struct crypto_alg *alg;

	struct lskcipher_instance *inst;

	int err;



	inst = skcipher_alloc_instance_simple(tmpl, tb);

	inst = lskcipher_alloc_instance_simple(tmpl, tb);

	if (IS_ERR(inst))

		return PTR_ERR(inst);



	alg = skcipher_ialg_simple(inst);



	err = -EINVAL;

	if (!is_power_of_2(alg->cra_blocksize))

	if (!is_power_of_2(inst->alg.co.base.cra_blocksize))

		goto out_free_inst;



	inst->alg.encrypt = crypto_cbc_encrypt;

	inst->alg.decrypt = crypto_cbc_decrypt;



	err = skcipher_register_instance(tmpl, inst);

	err = lskcipher_register_instance(tmpl, inst);

	if (err) {

out_free_inst:

		inst->free(inst);